System and method for locating fluid leaks at a drape of a reduced pressure delivery system

ABSTRACT

A system and method for performing tissue therapy may include applying a reduced pressure to a tissue site of a patient. A fluid parameter associated with applying a reduced pressureto the tissue site may be sensed. An audible fluid leak location sound may be generated in response to sensing the fluid parameter. The audible fluid leak location sound may be altered in response to sensing that the fluid parameter changes. By altering the audible fluid leak location sound in response to sensing a change of the fluid parameter, a clinician may detect location of a fluid leak at the drape by applying force to the drape. The force applied to the drape may be a clinician pressing a finger onto an edge of the drape.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application claims priority to Provisional Patent Applicationhaving Ser. No. 60/845,993 and filed on Sep. 19, 2006, the entirecontents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to a system and method of promotingtissue growth, and more specifically, a method for detecting andcorrecting fluid leaks at a drape positioned at a tissue site beingtreated by a reduced pressure delivery system.

2. Description of Related Art

Tissue growth and wound healing of patients has been shown to beaccelerated through the use of applying reduced pressure to a tissuesite. Reduced pressure delivery systems operate to form such a reducedpressure at a tissue site of a patient. This form of wound healing canbe readily integrated into a clinician's wound healing procedures.Reduced pressure tissue therapy optimizes patient care and decreasescosts associated with treatment of patients having traumatic and chronicwounds. Reduced pressure therapy can be administered in hospitals,community settings, such as assisted living complexes and convalescenceshomes, or homes of patients.

Reduced pressure delivery to a wound or tissue site promotes woundhealing and/or tissue growth, in part, by removing infectious materialsand other fluids from the wound or tissue site. Reduced pressuretreatment further promotes tissue growth by imposing forces on thetissue, thereby causing micro-deformation of the tissue, which isbelieved to contribute to the development of granulation tissue at thetissue site. The forces imposed on the tissue site by the delivery ofreduced pressure further encourages improved blood flow at the tissuesite, which further assists in the growth of new tissue.

Reduced pressure delivery systems generally use a vacuum pump to apply areduced pressure via a reduced pressure conduit to a tissue site. Amanifold is often used at the tissue site to help evenly distribute thereduced pressure. A drape is typically used to cover the manifold andform a seal with surrounding tissue of the tissue site to which thereduced pressure is being applied. So that the reduced pressure remainsconstant and accurate, thereby providing optimum tissue growth and/ortherapy, the drape is to be interfaced and maintained with thesurrounding tissue of the tissue site to prevent fluid leaks, such asair leaks. In the event that a fluid leak results during installation ofthe drape or during treatment, clinicians often find it difficult toisolate the precise location of the fluid leak. If the fluid leak is notcorrected, then the performance of the reduced pressure delivery systemis reduced and full treatment potential is not realized.

SUMMARY OF THE INVENTION

To overcome the problem of locating fluid leaks at an interface betweena drape and tissue of a patient, the principles of the present inventionprovide for detecting location of and correcting fluid leaks at thedrape of reduced pressure delivery systems. By being able to locatefluid leaks at the drape and tissue interface, optimum therapeuticresults may be produced.

One embodiment of a system for performing tissue therapy includes aprocessing unit and a reduced pressure source. A conduit may be fluidlyconnected between the reduced pressure source and a tissue site of apatient. The conduit may be configured to apply a reduced pressureproduced by the reduced pressure source to the tissue site. A drape maybe configured for positioning over the tissue site to maintain thereduced pressure at the tissue site. A fluid sensor may be in fluidcommunication with the conduit and in electrical communication with theprocessing unit. The fluid sensor may be configured to sense a fluidparameter within the conduit and generate a fluid sensor signal inresponse to sensing the fluid parameter. The fluid parameter may befluid flow rate, fluid pressure, or otherwise. The fluid sensor mayalter the fluid sensor signal in response to sensing that the fluidparameter changes. An electronic speaker may be in communication withthe processing unit. The processing unit may be configured tocommunicate a fluid leak location signal to the speaker to generate anaudible fluid leak location sound. The processing unit may further beconfigured to alter the fluid leak location signal in response to thefluid parameter being altered. The fluid leak location signal may bealtered in pitch, frequency, volume, or other audible sound parameter tocause the audible fluid leak location sound to be altered, therebyproviding an indication to a clinician attempting to locate the fluidleak at the drape that he or she is affecting the fluid leak.

One embodiment of a method for performing tissue therapy may includeapplying a reduced pressure to a tissue site of a patient. A fluidparameter associated with applying a reduced pressure to the tissue sitemay be sensed. An audible fluid leak location sound may be generated inresponse to sensing the fluid parameter. The audible fluid leak locationsound may be altered in response to sensing that the fluid parameterchanges. By altering the audible fluid leak location sound in responseto sensing a change of the fluid parameter, a clinician may detectlocation of a fluid leak at the drape by applying force to the drape.The force applied to the drape may be a clinician pressing a finger ontoan edge of the drape.

One embodiment of a method for locating a fluid leak while treating atissue site of a patient may include a clinician listening to an audiblesound generated by a reduced pressure delivery system. The clinician mayapply a force to a drape at the tissue site and the audible sound may belisted to for an audible change. The audible sound may change frequency,volume, or any other audible sound parameter. The location of the fluidleak may be determined at the interface between the tissue of thepatient and the drape based on the change in the audible sound. Thefluid leak may be reduced by the clinician once the fluid leak islocated.

Another method for determining a fluid leak while treating a tissue siteof a patient may include a clinician listening to an audible sound andapplying a force to a first region of the drape. The clinician maylisten for a change in audible sound in response to applying the forceto the first region of the drape. If the audible sound changes, then thefirst region of the drape may be corrected to reduce the fluid leak.Otherwise, a force may be applied to a second region of the drape. Ifthe audible sound changes in response to applying the force to thesecond region of the drape, then the second region of the drape may becorrected to reduce the fluid leak. A clinician may continue applyingforce to different regions of the drape and listen for a change in theaudible sound to determine a specific region where a fluid leak existsat the interface of the drape and tissue of the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the presentinvention may be obtained by reference to the following DetailedDescription when taken in conjunction with the accompanying Drawingswherein:

FIG. 1 is an illustration of an exemplary configuration of a patientbeing treated using a reduced pressure delivery system;

FIG. 2 is an illustration of an exemplary drape covering a tissue siteto which reduced pressure is being applied by a reduced pressuredelivery system;

FIG. 3 is an illustration of an exemplary drape covering a tissue siteto which reduced pressure is being applied by a reduced pressuredelivery system;

FIG. 4 is a block diagram of an exemplary reduced pressure deliverysystem configured to apply reduced pressure to a tissue site and notifya clinician that a fluid leak is occurring at the drape;

FIG. 5 is a screen shot of an exemplary graphical user interface thatenables a clinician to select a “seal check” function to locate fluidleaks that exist at the drape;

FIG. 6A is a screen shot of another exemplary graphical user interfaceof a reduced pressure delivery system showing an embodiment for enablinga clinician to select a mode for the reduced pressure delivery system todetermine whether any fluid leaks exist at the drape;

FIGS. 6B-6I are depictions of exemplary indicators for display on thegraphical user interface of FIG. 6A to enable a clinician to view whilelocating a fluid leak at a drape;

FIG. 7 is a flow chart of an exemplary process for generating an audiblefluid leak location sound to notify a user that a fluid leak exist atthe drape;

FIG. 8 is a flow chart of an exemplary process for a user to locate afluid leak at the drape; and

FIG. 9 is a flow chart of an exemplary process for locating andcorrecting a fluid leak in accordance with the principles of the presentinvention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

With regard to FIG. 1, a setup 100 for treating a patient 102 is shown.The patient is receiving reduced pressure treatment at a tissue site 104by a reduced pressure delivery system 106. The reduced pressure deliverysystem 106 may include a reduced pressure conduit 108 that extends fromthe reduced pressure delivery system 106 to the tissue site 104. At thetissue site 104, a reduced pressure dressing or distribution manifold110 may be fluidly connected to the reduced pressure conduit 108. Inaddition, a drape 112 may be placed over the tissue site 104 anddistribution manifold 110. The drape 112 may be a flexible material thatis impermeable to gases to prevent air or other fluids from entering orexiting the tissue site 104 during reduced pressure treatment.

As used herein, the term “flexible” refers to an object or material thatis able to be bent or flexed. Elastomer materials are typicallyflexible, but reference to flexible materials herein does notnecessarily limit material selection to only elastomers. The use of theterm “flexible” in connection with a material or reduced pressuredelivery apparatus in accordance with the principles of the presentinvention generally refers to the material's ability to conform to orclosely match the shape of a tissue site. For example, the flexiblenature of a reduced pressure delivery apparatus used to treat a bonedefect may allow the apparatus to be wrapped or folded around theportion of the bone having the defect.

The term “fluid” as used herein generally refers to a gas or liquid, butmay also include any other flowable material, including but not limitedto gels, colloids, and foams. One example of a gas is air.

The term “impermeable” as used herein generally refers to the ability ofa membrane, cover, sheet, or other substance to block or slow thetransmission of either liquids or gas. Impermeable may be used to referto covers, sheets, or other membranes that are resistant to thetransmission of liquids, while allowing gases to transmit through themembrane. While an impermeable membrane may be liquid type, the membranemay simply reduce the transmission rate of all or only certain liquids.The use of the term “impermeable” is not meant to imply that animpermeable membrane is above or below any particular industry standardmeasurement for impermeability, such as a particular value of watervapor transfer rate (WVTR).

The term “manifold” as used herein generally refers to a substance orstructure that is provided to assist in applying reduced pressure to,delivering fluids to, or removing fluids from a tissue site. A manifoldtypically includes a plurality of flow channels or pathways thatinterconnect to improve distribution of fluids provided to and removedfrom the area of tissue around the manifold. Examples of manifolds mayinclude, without limitation, devices that have structural elementsarranged to form slow channels, cellular foams, such as open-desk cellfoam, porous tissue collections, and liquids, gels and foams thatinclude or cure to include flow channels.

The term “reduced pressure” as used herein generally refers to apressure less than the ambient pressure at a tissue site that is beingsubjected to treatment. In most cases, this reduced pressure will beless than the atmosphere pressure at which the patient is located.Alternatively, the reduced pressure may be less than a hydrostaticpressure of tissue at the tissue site. Although the terms “vacuum” and“negative pressure” may be used to describe the pressure applied to thetissue site, the actual pressure applied to the tissue site may besignificantly less than the pressure normally associated with a completevacuum. Reduced pressure may initially generate fluid flow in the tubeor conduit in the area of the tissue site. As the hydrostatic pressurearound the tissue site approaches the desired reduced pressure, the flowmay subside, and the reduced pressure is then maintained. Unlessotherwise indicated, values of pressures stated herein are gagepressures.

The term “scaffold” as used herein refers to a substance or structureused to enhance or promote the growth of cells and/or the formation oftissue. A scaffold is typically a three dimensional porous structurethat provides a template for cell growth. The scaffold may be infusedwith, coated with, or comprised of cells, growth factors, or othernutrients to promote cell growth. A scaffold may be used as a manifoldin accordance with the embodiments described herein to administerreduced pressure tissue treatment to a tissue site.

The term “tissue site” as used herein refers to a wound or defectlocated on or within any tissue, including but not limited to, bonetissue, adipose tissue, muscle tissue, neuro tissue, dermal tissue,vascular tissue, connective tissue, cartilage, tendons, or ligaments.The term “tissue site” may further refer to areas of any tissue that arenot necessarily wounded or defective, but are instead areas in which itis desired to add or promote the growth of additional tissue. Forexample, reduced pressure tissue treatment may be used in certain tissueareas to grow additional tissue that may be harvested and transplantedto another tissue location.

The term “clinician” is used herein as meaning any medical professional,user, family member of a patient, or patient who interacts or interfaceswith a reduced pressure delivery system.

With regard to FIG. 2, a tissue site 200 on a person's body 202 isreceiving reduced pressure therapy from a reduced pressure deliverysystem (not shown). The reduced pressure delivery system is connected toa reduced pressure conduit 204 and in fluid communication with adistribution manifold (not shown), either directly or via an adapter206. A drape 208 may be configured to cover the distribution manifold,which is shown to be pressing into the drape 208 to form an outline 210.The drape 208 covers the tissue site 200, thereby helping to maintain aseal at the tissue site so that fluids, such as air, cannot enter orexit the tissue site. By preventing fluids from entering or exiting thetissue site 200, the tissue site 200 may receive maximum benefit of thereduced pressure therapy, including minimizing chance for additionalinfection and improving growth of tissue.

In establishing a dressing, which may include the distribution manifoldand drape 208, at the tissue site 200, a clinician may apply thedressing and apply a force to the drape 208 during operation of thereduced pressure delivery system. By applying a force along outer edgesof the drape 208, the clinician may create or otherwise alter a seal atan intersection 212 of the drape 208 and tissue 214 surrounding thetissue site 200. In the event that the seal is not completely formed ora fluid leak develops at the drape 208, the clinician may press his orher finger 216 along the outer edges 212 of the drape 208 to improve orre-establish the seal. Because locating a fluid leak at the drape 208 isoften difficult in practice, the principles of the present inventionprovide a system and method for determining location of the fluid leak,as further described herein with respect to FIGS. 4-8.

With regard to FIG. 3, a cutout view of the tissue site 200 is providedto show the drape 208 extending over healthy tissue 302 surrounding thetissue site 200. The drape 208 extends over manifold 304, which is influid communication with reduced pressure conduit 306. The reducedpressure conduit 306 is further in fluid communication with reducedpressure delivery system 308. The reduced pressure therapy system 308may include a vacuum pump 310 and electronic display 312. The electronicdisplay 312 may include control elements 314 a-314 n (collectively 314)that may be used by a user operating the reduced pressure deliverysystem 308. In addition or alternatively, the electronic display 312 mayinclude a touch-screen electronic display 316 that enables the user tointerface with and operate the reduced pressure delivery system 308.

The drape 208 that extends over the healthy tissue 302 forms a seal atan intersection 318 where the healthy tissue 302 and drape 208 contactone another. If a fluid leak develops at the intersection 318 (i.e., atthe tissue site 200), then a fluid leak sensor (not shown) may generateand communicate a fluid leak signal. The fluid leak signal may beindicative of a fluid parameter indicative of or responsive to the fluidleak crossing a predetermined threshold level. A processing unit (notshown) may respond by generating a fluid leak alarm in an audible and/orvisual manner. For example, a buzzer, bell, recorded message, or otheraudible sound may be generated to alert a clinician that a fluid leakhas occurred at the drape 208. To locate the fluid leak at the drape208, a fluid leak location mode may be automatically or manually enteredat the reduced pressure delivery system 308. The fluid leak locationmode may be used to enable the clinician to apply a force, such aspressing a finger along the drape 208, such as pressing at theintersection 318. As the clinician applies the force, in response to theclinician applying a force to the location of the fluid leak, thereduced pressure delivery system 308 may generate an audible sound thatchanges. The audible sound may be decreased in pitch or volume, forexample, to enable the clinician to identify a location at the drape 208at which a fluid leak exists.

With regard to FIG. 4, a configuration 400 of a reduced pressuredelivery system 402 is shown to be operating to apply a reduced pressureto tissue site 404. The reduced pressure delivery system 402 may includea printed circuit board 406 that includes a processing unit 408. Theprocessing unit 408 may include one or more processors, logic, analogcomponents, or any other electronics that enable signals includinginformation, such as fluid pressure at a tissue site, to be received.The processing unit 408 may process the information provided by thesignals. For example, a fluid leak signal may be received by theprocessing unit 408 and a fluid leak alarm and/or fluid leak locationprocess may be driven by the processing unit 408.

The reduced pressure delivery system 402 may further include a pump 410,such as a vacuum pump, that may be driven by a motor 412. The motor 412may be in electrical communication with the PCB 406 and respond tocontrol signals 414 generated by the PCB 406. The pump 410 may befluidly connected to a reduced pressure conduit 416. The reducedpressure conduit 416 may include an orifice 418 that operates as arelief valve. In parallel with the orifice is a flow transducer 420 thatmay be configured to determine flow rate of fluid passing through thereduced pressure conduit 416. The flow transducer 420 is fluidlyconnected to the reduced pressure conduit 416 and configured to generatea flow rate signal 422 including information indicative of flow rate ofa fluid within the reduced pressure conduit 416. The flow rate signal422 may be digital or analog.

A pump pressure transducer 424 may be connected to reduced pressureconduit 416 to convert pressure in the reduced pressure conduit 416 andcommunicate a pump pressure signal 426 including information indicativeof fluid pressure in the reduced pressure conduit 416 to the PCB 406.The pump pressure signal 426 may be digital or analog. A pump releasevalve 428 may also be connected to the reduced pressure conduit 416 andbe configured to release pressure from the reduced pressure conduit 416in case of an emergency situation or otherwise.

The reduced pressure delivery system 402 may further include one or morefilters 430 a-430 n (collectively 430) that are in fluid communicationwith the reduced pressure conduit 416. The filters 430 may be in fluidcommunication with container 432, which is used to collect fluids fromtissue site 404. The filters 430 may be configured to prevent fluidscollected in the container 432 from entering the reduced pressureconduit 416. The container 432 may further be in fluid communicationwith reduced pressure conduit 434. Although shown as separate conduits,the reduced pressure conduits 416 and 434 may be the same or differentmaterial and have the same or different dimensions. The reduced pressureconduit 434 may connect to or be in fluid communication with an adapter436, which may be connected to a distribution manifold 438 to evenlydistribute reduced pressure across the tissue site 404. Drape 440, whichextends over the tissue site and onto tissue 442 surrounding the tissuesite 404 being treated by the reduced pressure is used to form a seal toform and maintain reduced pressure at the tissue site 404.

A feedback reduced pressure conduit 444 may pass through container 432.A tissue release valve 446 may be connected to the feedback reducedpressure conduit 444 to enable pressure to be released at the tissuesite 404 in response to a command signal 448 generated by the processingunit 408. The command signal 448 may be generated by the processing unit408 in response to the processing unit 408 receiving a sensor signal,such as flow rate signal 422, crossing a threshold level. Alternatively,the command signal 448 may be generated in response to a clinicianselectively stopping the reduced pressure delivery system 402 via a userinterface (not shown). Other events, such as a treatment cyclecompleting, may cause the processing unit to generate the command signal448 to activate the tissue release valve 446. In another example, atissue pressure transducer 450 may be used to convert pressure sensed atthe tissue site 404 and provide a feedback signal 452 to the processingunit 408 on the PCB 406. In response to the processing unit 408determining that pressure at the tissue site 404 sensed by the tissuepressure transducer 450 is above a threshold value, the processing unit408 may communicate command signal 448 to the tissue release valve 446for release of tissue pressure.

An electronic speaker 454 may be in electrical communication with thePCB 406 to generate an audible sound. In the event that the processingunit 408 determines that a fluid parameter, such as pressure at thetissue site 404 or flow rate of fluid through the reduced pressureconduit 416, crosses a threshold value, a signal 456 may be generated bythe PCB 406 and communicated to the electronic speaker 454 to create anaudible sound. For example, the processing unit 408 may determine that afluid leak exists at the tissue site 404 by a fluid rate increasingabove a flow rate threshold level. In response to determining that theflow rate level sensed by a flow transducer, such as flow transducer420, the processing unit 408 may generate the signal 456, such as analert signal, and communicate the alert signal to the electronic speaker454 to notify a clinician that a problem exists. In another example, asensor, such as tissue pressure transducer 450, may sense a fluidparameter at the tissue site 404 and the processing unit 408 maydetermine that the pressure at the tissue site 404 decreases. Still yet,rather than directly sensing a fluid parameter, an indirect measurementmay be performed by measuring duty cycle or power of the pump 410 todetermine approximate fluid flow. The processing unit 408 may beselectively programmed or commanded into a fluid leak location mode toenable the clinician to locate the fluid leak at the drape 440 byapplying a force on the edges of the drape 440. The processing unit 408may generate a continuous or discontinuous fluid leak location signaland drive the electronic speaker 454 to enable the clinician todetermine a location of the fluid leak at the drape 440.

Although the fluid leak location mode is helpful for locating a fluidleak at the drape, it should be understood that the fluid leak locationmode may enable the clinician or technician to locate a fluid leak atthe reduced pressure delivery system. For example, should a leak occurat a conduit connection or at a seal, the fluid leak location may helpin locating such a fluid leak. In one embodiment, an adapter (not shown)may be provided to cause reduced pressure conduits to simulate operationwith a complete drape seal to enable locating a fluid leak at or withinthe reduced pressure delivery system.

With respect to FIG. 5, a reduced pressure delivery system 500 mayinclude an electronic display 502 that is configured to display agraphical user interface (GUI) 504. The GUI 504 may include a number ofselectable graphical elements, including a “settings” soft-button 506,“wound type” soft-button 508, “seal check” soft-button 510, and“history” soft-button 512. A user may select any of these functions(i.e., settings, wound type, seal check, or history), to cause thereduced pressure delivery system 500 to present the user with anothergraphical user interface for performing the selected function. Inaddition, an “exit” soft-button 514 may be available to the user to exitthe current GUI 504. It should be understood that the GUI 504 isexemplary and that other and/or alternative functions and selectionelements may be provided to the user.

An information region 516 on the GUI 504 may include selectablegraphical elements and display other information in which the user maybe interested. For example, a “help” soft-button 518 may be displayed toenable the user to receive help about the reduced pressure deliverysystem 500 or particular functions currently being displayed on the GUI504. An “on-off” soft-button 520 may enable a user to selectively turnthe reduced pressure delivery system 500 on and off, and information 522may notify the user of current status of the reduced therapy deliverysystem 500. For example, the status information 522 may indicate thatthe reduced therapy delivery system 500 is (i) operating in a continuoustherapy mode, (ii) is on, and (iii) is operating to provide a reducedpressure of 200 mmHg. A “lock” soft-button 524 may enable the user tolock the GUI 504 to prevent an inadvertent contact with the GUI 504 tocause the reduced therapy delivery system 500 to respond.

With regard to FIG. 6A, the reduced pressure delivery system 500 maydisplay GUI 602 on the electronic display 502 in response to a userselecting the “seal check” soft-button 510 on the GUI 504 of FIG. 5. TheGUI 602 may display a graphical indicator 604 indicative of a fluidparameter, such as fluid pressure or fluid flow rate, being sensed by asensor of the reduced pressure delivery system 500. As shown, thegraphical indicator 604 is a bar indicator having three levels,including low, medium, and high. The graphical indicator 604 may show adynamic portion 606 that increases and decreases based on the fluidparameter being sensed by the sensor (e.g., flow rate sensor or pressuresensor) of the reduced pressure delivery system 500. The height of thedynamic region 606 may indicate the amount of fluid leak currently beingsensed at a tissue site. Although the graphical indicator 604 may behelpful to a clinician to determine location of a fluid leak at a drapecovering a tissue site, depending upon the arrangement of the reducedpressure delivery system 500 at a patient's bed, a clinician may or maynot be able to view the graphical indicator 604 as he or she isattempting to locate a fluid leak at the drape.

So that the clinician may more easily locate the fluid leak at thedrape, the reduced pressure delivery system 500 may generate an audiblesound indicative of a level of a fluid parameter sensed by a sensor ofthe reduced pressure delivery system 500. The clinician may select a“seal audio” soft-button 608 to toggle or mute and unmute an audiblefluid leak location sound off and on (i.e., mute and unmute). Theaudible fluid leak location sound may be altered in response to thefluid parameter being sensed changing. For example, if pressure at thetissue site increases in response to the clinician pressing on thedrape, the audible fluid leak location sound may be altered to indicateto the clinician that the fluid leak is being or has been sealed and,therefore, located. The audible fluid leak location sound may change infrequency, volume, or pitch. Alternatively, a “Geiger counter” sound maybe produced during the seal check, where a tone speed increases ordecreases depending upon the change of fluid parameter. For example, ifthe clinician is “cold” with respect to the location of the fluid leak,the Geiger counter sound may beep slowly. When the clinician presses ator near the fluid leak of the drape, then the Geiger counter sound mayincrease as the pressure at the tissue site as the fluid leak is sealeduntil a continuous tone occur when the drape is completely sealed and amaximum pressure or pressure above a seal pressure threshold level isachieved. In another embodiment, the audible fluid leak location soundmay be a recorded message, such as “cold,” “warmer,” and “hot.” Inanother example, a “water dripping” sound may be generated to representthat a fluid leak (e.g., air leak) exists. It should be understood thatnearly any sound may be utilized to indicate to the clinician that afluid leak exists or is being sealed to help the clinician locate thefluid leak. Because a human ear is more sensitive than human eyes, theuse of an audible sound to indicate status of a fluid parameter mayenable the clinician to more easily determine location of the fluid leakat the drape than a graphical indicator. As understood in the art, gas(e.g., air) is primarily the fluid that is leaked at the drape.

With regard to FIG. 6B, a bar indicator 610 a may display a dynamicregion 612 a indicative of a level of fluid leakage parameter (e.g.,pressure). The dynamic region 612 a is shown to be within a “low” fluidleakage level and have a corresponding pattern (e.g., lightly shaded) orcolor (e.g., green). A threshold level indicia 614 may be representativeof a threshold level that may be preset by a clinician or manufacturerof the reduced pressure delivery system 500 of FIG. 6A, where an alarmor other response may be generated in response to the fluid leakageparameter crossing the threshold level. As shown on the bar indicator610 a in FIG. 6C, the dynamic region 612 b increases above the thresholdlevel indicia 614, thereby, in one embodiment, causing an alarm to begenerated and the reduced pressure delivery system 500 to enter into aleak location mode to enable a clinician to locate a leak at the drapeor elsewhere. The dynamic region 612 b may be changed in pattern (e.g.,medium shade) or color (e.g., yellow) to represent that the fluidparameter is currently in the medium range. If, for example, the fluidparameter increases to cause the dynamic region 612 to enter into a highrange, then the dynamic region 612 may be changed in pattern (e.g.,solid color) or color (e.g., red). Other graphical features may be used,such as flashing or otherwise, to provide the clinician with visualinformation to make it easier to locate a fluid leak at the drape.

With regard to FIG. 6D, a time sequence 616 a is shown to include anumber of graphic bars 618 a-618 n over a time period between time T₀and T_(n). Graphic bars 618 a-618 n indicate that the fluid parameter isstable and at a low fluid leakage level. However, as shown in FIG. 6E,graphic bar 618 n+4 at time T_(n+4) increases above threshold level 620.

With regard to FIGS. 6F and 6G, a fluid leakage rate is shownalpha-numerically in display fields 622 a and 622 b, respectively. Asshown, the fluid leakage rate is at “1,” which represents a low levelleakage, in FIG. 6F and “5,” which represents a higher level leakage, inFIG. 6G. In one embodiment, ranges between 0-3 may represent a low levelleakage, 4-6 may represent a medium level leakage, and 7-10 mayrepresent a high level leakage. Each level of leakage may represent acorresponding flow rate or pressure level and the digits may changecolor (e.g., green, orange, and red) depending on the fluid leakagelevel. In an alternative embodiment, letters, such as “A”-“F,” may bedisplayed.

With regard to FIGS. 6H and 6I, pie charts 624 a and 624 b,respectively, may be displayed that show leakage levels 626 a and 626 b,respectively, that indicate fluid leakage during operation of a tissuetreatment system. One or more threshold levels 628 may be shown and usedto identify when a fluid leakage exceeds the threshold, thereby causinga fluid leakage alarm to be initiated. If multiple threshold levels areused, each may represent a different leakage level (e.g., low, medium,or high) and may cause a different alarm, audible and/or visual, to beinitiated. Depending on the level of the fluid leakage rate, the coloror pattern may change. In addition, an audible sound may be altered inresponse to the fluid leakage rate increasing or decreasing above orbelow a threshold level.

With regard to FIG. 7, a process 700 for determining location of a fluidleak is provided. The process 700 starts at step 702, where a reducedpressure may be applied to a tissue site. At step 704, a fluid parameterassociated with the reduced pressure may be sensed. The fluid parametermay include a fluid flow rate, fluid pressure, or otherwise. In oneembodiment, the fluid parameter is sensed at the tissue site. In anotherembodiment, the fluid parameter is sensed in a reduced pressure conduitof the reduced pressure delivery system. It should be understood thatthe fluid parameter may be sensed by any type of sensor that issensitive enough to sense changes in the fluid parameter that aremeaningful to a clinician when attempting to locate and seal a fluidleak. For example, a fluid flow transducer may be configured to sensechanges in fluid flow rate between approximately 0.1 liters per minuteand 2.0 liters per minute and have a resolution of approximately 0.01liters per minute.

At step 706, an audible fluid leak location sound may be generated inresponse to sensing the fluid parameter. The audible fluid leak locationsound may be one of a variety of different sounds. Continuous tones withvarying frequency, pitch or volume, for example, may be utilized.Alternatively, discrete tones with varying length or frequency may beutilized. Still yet, recorded messages, sounds, or otherwise may beutilized. It should be understood that any sound or combination ofsounds may be utilized as an audible fluid leak location sound. At step708, the audible fluid leak location sound may be altered in response tosensing fluid parameter changes. The altered audible fluid leak locationsound may be altered in frequency, pitch, volume, or otherwise. Byaltering the audible fluid leak location sound, the clinician attemptingto locate a fluid leak at the drape may more easily determine thelocation of the fluid leak, thereby enabling the fluid leak to besealed.

With regard to FIG. 8, a process 800 for determining a location andreducing a fluid leak at a drape may be performed. The process 800 maystart at step 802, where a determination that a fluid leak exists at adrape may be made. A fluid leak alarm may be generated by a reducedpressure delivery system in response to a fluid parameter increasingabove or below a threshold level. At step 804, a clinician may listen toan audible sound. The audible sound may be an audible fluid leaklocation sound that is started in response to the fluid leak beingautomatically determined or by the clinician selecting to operate a sealcheck via a graphical user interface. At step 806, the clinician mayapply a force to the drape covering the tissue site. The force may beapplied by the clinician's finger pressing on a spot at a perimeterlocation of the drape. The clinician may listen for a change in theaudible sound in response to applying the force to the drape at step808. The clinician may continue to apply force to different locations onthe drape and listen for changes in the audible sounds in response toapplying the force at different locations of the drape until adetermination of a location of the fluid leak at the drape may be madeat step 810. The audible sound may indicate that the fluid leak has beensealed at step 812.

Regarding FIG. 9, an exemplary process for locating and correcting afluid leak is provided. The process starts at step 902, where fluidpressures are monitored. The fluid pressures may be monitored using apressure transducer or otherwise. At step 904, a determination as towhether a pressure threshold level is exceeded is made. If the pressurethreshold level is not exceeded, then the process returns to step 902.If the pressure threshold level is exceeded, then the process continuesat step 906, where an audible and visual fluid leak alarm is activatedor otherwise initiated. The process continues at step 908, where thefluid leak alarm is reset by a clinician.

At step 910, the clinician may select a fluid leak located tool orfunction of the tissue treatment system. An audible and visualrepresentation of leak magnitude may be activated at step 912 to show afluid leak level, or indication thereof from flow rate or pressure beingsensed in the tissue treatment system. At step 914, the clinician mayuse his or her hands or fingers to cover possible fluid leak locationsat a drape covering a tissue site. During this time, a time-outdetermination may be performed at step 916. If the system is nottimed-out, then the process repeats step 914. Alternatively, if thesystem is determined to time-out, then the process continues at step918, where reduced pressure therapy is interrupted. The processcontinues at step 920 after step 914 where the fluid leak is at leastpartially occluded or otherwise stopped. In response to the fluid leakbeing partially occluded, the audible and visual representation of thefluid leak is altered to indicate the decreased fluid leak at step 922.At step 924, the fluid leak is fixed by the clinician as he or she hasbeen able to locate the fluid leak at the drape. At step 926, inresponse to the fluid leak being fixed, the audible and visualrepresentation is altered to indicate fluid leakage dropping below athreshold level. At step 928, the reduced pressure therapy is continued.

The previous description is of preferred embodiments for implementingthe invention, and the scope of the invention should not necessarily belimited by this description. The scope of the present invention isinstead defined by the following claims.

1. A method for performing tissue therapy, comprising: applying areduced pressure to a tissue site of a patient; sensing a fluidparameter associated with applying the reduced pressure to the tissuesite; determining that a fluid leak exists in response to sensing thefluid parameter; generating an audible fluid leak location sound inresponse to determining that a fluid leak exists, the audible fluid leaklocation sound having an ON state and an OFF state, and being variablein the ON state; and altering the audible fluid leak location soundwhile in the ON state in response to sensing that the fluid parameterchanges.
 2. The method according to claim 1, wherein altering theaudible fluid leak location sound includes altering an audible frequencyof the audible fluid leak location sound in response to sensing analtered fluid parameter.
 3. The method according to claim 1, whereinaltering the audible fluid leak location sound includes alteringduration of the audible fluid leak location sound in response to sensingan altered fluid parameter.
 4. The method according to claim 1, whereinaltering the audible fluid leak location sound includes alteringamplitude of the audible fluid leak location sound in response tosensing an altered fluid parameter.
 5. The method according to claim 1,further comprising: determining that the fluid parameter crosses athreshold value; and generating an audible alarm signal in response todetermining that the fluid parameter crossed the threshold value.
 6. Themethod according to claim 1, further comprising displaying a graphicaluser interface that includes a selectable element that, when selected,causes a fluid leak location detection mode to be entered.
 7. The methodaccording to claim 6, further comprising generating a graphicalindicator indicative of the fluid parameter and changes of the fluidparameter while in the fluid leak location detection mode.
 8. The methodaccording to claim 1, further comprising: forming a seal with tissue ofthe patient to form a reduced pressure with the tissue site; andinitiating the audible fluid leak location signal.
 9. The methodaccording to claim 1, further comprising selectably toggling the fluidleak location signal on and off.
 10. The method according to claim 1,wherein sensing the fluid parameter includes electronically sensing anairflow or a pressure.
 11. The method according to claim 1, whereinaltering the fluid leak location sound indicates whether a fluid leakcorresponding to the sensed fluid parameter is increasing or decreasing.12. A method for determining a fluid leak of a reduced pressure deliverysystem at an interface between a tissue of a patient and a drape of thereduced pressure delivery system, said method comprising: determiningthat a fluid leak exists at the interface between the tissue site of thepatient and the drape; listening to an audible sound generated inresponse to sensing a fluid parameter indicating the fluid leak at theinterface, the audible sound having an ON state and an OFF state, andbeing variable in the ON state; applying force to the drape; listeningfor a change in the audible sound generated while in the ON state inresponse to the fluid parameter changing based on application of theforce to the drape; determining a location of the fluid leak at theinterface between the tissue of the patient and the drape based on thechange in the audible sound, the audible sound indicating when the fluidleak increases or decreases; and reducing the fluid leak at the locationdetermined at the interface between the tissue of the patient and thedrape.
 13. The method according to claim 12, wherein the sensing isperformed electronically utilizing an airflow or a pressure, and whereinthe fluid leak is a gas leak.
 14. The method according to claim 12,wherein listening for a change in the audible sound includes listeningfor an audible frequency change of the audible sound.
 15. The methodaccording to claim 12, wherein listening for a change in the audiblesound includes listening for a duration change of the audible sound. 16.The method according to claim 12, wherein listening for a change in theaudible sound includes listening for an amplitude change of the audiblesound.
 17. The method according to claim 12, wherein determining that afluid leak exists at the interface includes hearing an audible alarmsound generated by the reduced pressure delivery system.
 18. The methodaccording to claim 12, wherein determining the location of the fluidleak at the interface includes viewing a graphical image displayed bythe reduced pressure delivery system indicative of a fluid leak changein response to applying force to the drape to determine the location ofthe fluid leak.
 19. The method according to claim 18, wherein watchingthe graphical image includes watching for the graphical image to changeat least one graphical characteristic.
 20. A method for determining afluid leak of a reduced pressure delivery system at an interface betweena tissue of a patient and a drape of the reduced pressure deliverysystem, said method comprising: determining that a fluid leak at theinterface between a tissue site of the patient and the drape, an audiblesound having an ON state and an OFF state, and being variable in the ONstate; listening to the audible sound generated in response to sensing afluid parameter indicating the fluid leak at the interface; applyingforce to a first region of the drape; listening for a change in theaudible sound generated while in the ON state in response to the fluidparameter changing in response to applying the force to the first regionof the drape, the generated audible sound indicating when the fluid leakincreases or decreases; if the generated audible sound changes while inthe ON state in response to applying the force to the first region ofthe drape, correcting the first region of the drape to reduce the fluidleak; otherwise, applying a force to a second region of the drape;listening for a change in the generated audible sound while in the ONstate in response to the fluid parameter changing in response toapplying the force to the second region of the drape; and if thegenerated audible sound changes while in the ON state in response toapplying the force to the second region of the drape, then correctingthe second region of the drape to reduce the fluid leak.
 21. The methodaccording to claim 20, wherein the sensing is performed electronicallyutilizing an airflow or a pressure, wherein the audible sound isgenerated by the reduced pressure delivery system, and wherein the fluidleak is a gas leak.
 22. The method according to claim 20, furthercomprising: determining that the generated audible sound does not changein response to applying the force to the second region of the drape;applying force to at least one different region of the drape until thegenerated audible sound changes; and in response to hearing thegenerated audible sound change, correcting the at least one region ofthe drape to which the force is being applied to reduce the fluid leak.23. The method according to claim 20, wherein listening for a change inthe generated audible sound includes listening for an audible frequencychange of the generated audible sound.
 24. The method according to claim20, wherein listening for a change in the generated audible soundincludes listening for a duration change of the generated audible sound.25. The method according to claim 20, wherein listening for a change inthe generated audible sound includes listening for an amplitude changeof the generated audible sound.
 26. The method according to claim 20,wherein determining that a fluid leak exists at the interface includeshearing an audible alarm sound.
 27. The method according to claim 20,wherein determining the location of the fluid leak at the interfaceincludes viewing a graphical image displayed that is indicative of afluid leak change in response to applying force to the drape todetermine the location of the fluid leak.
 28. The method according toclaim 27, wherein viewing the graphical image includes viewing for thegraphical image to change at least one graphical characteristic.
 29. Themethod according to claim 1, wherein applying a reduced pressureincludes applying a reduced pressure to the tissue site of the patientto reach a steady-state reduced pressure, and wherein generating theaudible fluid leak location sound includes generating an audible fluidleak location sound in response to sensing the fluid parameter changesfrom the steady-state reduced pressure.
 30. The method according toclaim 12, further comprising applying a reduced pressure to a tissuesite of the patient to reach a steady-state reduced pressure, andwherein determining that the fluid leak exists includes determining thatthe fluid leak exists after reaching the steady-state reduced pressureat the interface between the tissue site of the patient and the drape.31. The method according to claim 20, further comprising applying areduced pressure to a tissue site of the patient to reach a steady-statereduced pressure, and wherein determining that the fluid leak existsincludes determining that a fluid leak exists after reaching thesteady-state reduced pressure at the interface between a tissue site ofthe patient and the drape.
 32. The method according to claim 1, whereinaltering the audible fluid leak location sound includes alteringfrequency, volume, or tone speed of the audible fluid leak locationsound in response to sensing the fluid parameter changing.
 33. Themethod according to claim 32, wherein altering the audible fluid leaklocation sound includes continuously altering the audible fluid leaklocation sound in response to sensing the fluid parameter continuouslychanging.
 34. The method according to claim 12, wherein listening for achange in the audible sound includes listening for a change infrequency, volume, or tone speed of the audible sound in response tosensing the fluid parameter changing.
 35. The method according to claim34, wherein listening for a change in the audible sound includeslistening for a continuous change in the audible sound in response tosensing the fluid parameter continuously changing.
 36. The methodaccording to claim 20, wherein listening for a change in the audiblesound includes listening for a change in frequency, volume, or tonespeed of the audible sound in response to sensing the fluid parameterchanging.
 37. The method according to claim 36, wherein listening for achange in the audible sound includes listening for a continuous changein the audible sound in response to sensing the fluid parametercontinuously changing.